3BF Mechanical vs. String Linkage

[Fireinthebones]

On the brass exchange there is a 3BF Silversonic with its rotor having a mechanical linkage I have only ever seen king horns with string linkage was this an after market thing or was this stock and does anyone have opinions on this as I have always found their sideways triggers kind of hard to actuate.

[atopper333]

That is an interesting set up, looks kind of similar to the olds mechanical triggers but in reverse. I’ve had two horns upgraded from a string to a mechanical linkage. A Conn 88h and a YBL-322. Both were done exceptionally well, looked nice and had a short throw and excellent return.

The setup on that King may eliminate and ‘lateral’ movement when activating the trigger as there shouldn’t be any side to side play on the trigger…but that I guess would depend on how well done it is.

Honestly, I would give Doug a call and ask him how it is. I’ve bought four trombone through him, all have been awesome. His descriptions always have been spot on for me and, if you haven’t dealt with him before, he has a lot of experience and is a pleasure to speak with.

[BGuttman]

The old King 3B-F had a kidney-shaped metal linkage between rotor and lever. They never used this arrangement on the larger instruments (4B, 5B, 6B, 7B, or 8B) which had strings and a metal rod (later a plastic fitting) to hold a string.

[sstelmack]

I think my 3BF is from the 70's and looks just like this one. I am pretty sure I have seen others like it too. I think it is factory.

[glenp]

Mine has this linkage too, and I like it. Bought it here. Since I had never seen it before I asked and the seller said it was original. It’s also from the 70’s I believe.

[JohnL]

That's the old-style King linkage; my late 1940's Symphony model is similar. I think they changed over to the hybrid linkage sometime in the mid-1970's. You'll notice that the wrap is also different from what King uses now; they seem to have changed the wrap around the same time they changed the linkage.

Basically, they took the wrap layout and linkage from the then-new 4BF (a George McCracken design) and incorporated it into the 3BF.

[Burgerbob]

The linkage, paddle, and wrap all changed slowly.

Mine has the "modern" string linkage but the earlier style 90 degree wrap. Going back in production order, the horn I had before this had the mechanical linkage but wide paddle. The other one had skinny paddle.

[Windmill]

From what I can remember, my old 3B had this mechanical linkage, looked like this :

[Matt K]

That doesn't look stock to me. I think the stock mechanical linkages were similar to the string ones but with some kind of miniballs, right?

[Windmill]

Yes, this is not a king. But it looked like that... No Miniballs, just 2 screws. As the cinematic is all "in line", no need for ball joints Courtois used the same linkage for a while on the 200, 250 and 300 series.

[ithinknot]

similar to the string ones but with some kind of miniballs, right?

wrong ... for example

originally the 'kidney' bit was metal, later Delrin or similar

[Matt K]

What are those then, screws? I can’t quite tell from the angle

[Burgerbob]

Yup, looks like a super early example.

[Matt K]

Interesting. I’m kinda shocked at how good my 607 action is. It’s one of the plastic ones. With strings. I’m mildly concerned about it’s long term… well.. longevity. But I guess we’ll see how long it lasts!

[JohnL]

Interesting. I’m kinda shocked at how good my 607 action is.

From a mechanical standpoint, it's a great design, though there are those that find the ergonomics less than ideal.

[harrisonreed]

I like the kidney linkage. Yeah, I think it's just screwed into place with two screws.

[Jimkinkella]

It’s stock, I used to have that exact valve setup on a non-silversonic

[JohnL]

I like the kidney linkage. Yeah, I think it's just screwed into place with two screws.

The screws are only threaded part way to the head of the screw; the unthreaded portion forms the pivot.

[Windmill]

Yes, and I believe they switched to plastic materials to reduce the noise , when the screw holes would get slightly worn out and larger. On the Olds mechanism, which is technically similar but all metal, it's very well adjusted and the noise is amazingly low.